Prime Minister John Key and the Maori Party co-leaders are expected to meet this week to discuss Mr Key's comments about the Waitangi Tribunal - and members of the Iwi Leaders' Forum are also turning on Mr Key over the issue.

Forum member and Te Rarawa chairman Haami Piripi, who appeared before the Waitangi Tribunal last week, has accused Mr Key of misrepresenting the negotiations with iwi leaders by indicating they covered all issues to do with water.

Mr Piripi said the iwi leaders' water forum was restricted to issues about the management of water rather than Treaty claims which were specifically excluded from the talks.

Those talks have been ongoing for about four years and Mr Key has argued that the forum is the best place to nut out the rights issues rather than through the courts.

Mr Piripi said the talks would be helped by a strong recommendation from the Waitangi Tribunal, but were restricted.

He also extended an olive branch to the Maori Council, saying he backed it for taking the claim. There has been tension between the two groups over who acts for Maori, but Mr Piripi said the two could co-exist and even collaborate.

'I certainly know that if Maori iwi and the New Zealand Maori Council combined collaboratively together, we could mount a protest offensive against these sales that I think could easily sink them because it would create too much peril for potential investors. I hope we're not forced to."

Mr Piripi said it would be "very colonial" for Mr Key to ignore the Maori interest now and ride over the top of them by proceeding with the sale.

"I don't see how the asset sales regime can continue while ignoring the Maori interest."

The potential for the two bodies to join forces will cause a greater headache for Mr Key, who is also expected to meet with Maori Party co-leaders Tariana Turia and Pita Sharples this week.

They will discuss Mr Key's comments that the Government could ignore the Waitangi Tribunal's recommendations - something the co-leaders have interpreted as being dismissive of the tribunal.

The Crown opened its case at the hearing on Friday and will present the rest of its experts today, including energy consultant Lee Wilson and representatives from the Office of Treaty Settlements, the Ministry for the Environment and the Ministry of Foreign Affairs and Trade. Closing submissions are expected tomorrow.

Crown lawyer Paul Radich has argued that although it was accepted Maori had rights, the sale of shares in SOEs will not affect Maori rights or reduce the ability of the Crown to address those rights.

Maori Council co-chairman Maanu Paul said if the Crown believed Maori did have rights over water, those rights should be specified and a way found to recognise those before any shares were sold.